Photographic developer



Patented Dec. 5, 1939 UNITED STATES PATENT- OFFICE PHOTQGRAPHIC DEVELOPER No Drawing. Application December 8, 1937,

Serialv No. 178,726. In Germany December M,

1936 4 Claims.

The present invention relates to photographic developers.

One of its objects is to provide'a photographic developer containing special hydroxyalkylamines. Other objects will appear from the detailed specification following hereinafter.

For the development of latent photographic images, especially in halide silver emulsions, alkaline developers have long been used. The alkalinity of these developers consisting of a mixture of several substances normally is due to the presence of an alkali hydroxide or an alkali carbonate. 'A series of light-sensitive substances 7 agents for photographic developers.

introduced into the art which requires the use of substances of asmaller degree of alkalinity than, for example, caustic potash or soda. When inorganic carbonates are used the evolution of bubbles of gas (carbon dioxide) is likely to occur with injurious efiect if the photographic material is transferred from the alkaline developer into anacid fixing bath or intermediate bath. For these reasons attempts have been made to find a suitable substitute for inorganic alkalies;

On several occasions triethanolamine (in the form of the free base or a salt thereof) as well as the hydroxyalkylamines generally have been suggested as a substitute. These compounds,

:n being at least 1) alsoh ave a strong alkalinity and a tendency to absorb carbon dioxide. Moreover, all of these agents which are preferable for the purpose are liquid and many have a disagreeable odor and therefore are not suitable for the production of developing commercial use.

This invention is based on the observation that aliphatic hydromalkylamines which instead of only one hydroxyl group in one alkyl group contain in at least one alkyl chain two or several hydroxyl groups combined with difierent carbon atoms serve in a surprising manner as alkaline They correspond generally with the formula which are essentially characterized by the groupmixtures for tion:

(on. as-say wherein R1=H or aralkyl or alkyl or hydroxyalkyl or p ly ydr va y R2=H or aralkyl or alkyl or hydroxyalkyl or polyhydroxyalkyl, a:=at least 1, y=at least 2, 2:0 or 1 or more.

The hydroxyl groups may be free or etherifled or esterified; internal ethers are also useful. It is necessary that the compound should'be well soluble in water. Such polyhydroxyalkylamines are especially amino-derivatives of the sugars and carbohydrates having 5 and 6 carbon atoms but also lower and higher homologues may be used. In the hydroxyalkyl chain the carbon atoms combined with the hydroxyl groups may also be separated by one or more C-atoms without a hydroxyl group. Without implying that the other bodies conforming withthe above formulae are unsuitable or little suitable, there may be mentioned here as especially suitable substances the following: glucamine, methyl-, ethyl-, propyl-, dodecyl-glucamine, mannamine, galactamine, lactamine, fructamine, arabinamine, xylamine, 1- or v2-aminopropane diol.

Most of these compounds are easily and cheaply obtained from the sugars by aminating them under reducing conditions, see for instance Richter-Anschiitz, Chemie der Kohlenstofiverbindungen, 1. 12, (1928) 742 and'751, and E. Roux, Bulletin de la Socit Chimique de France (3) 25, 586 (1901), Comptes, Rendus de IAcademie des Sciences (1903) 1079, 1081 and Chemisches Zentralblatt (1904) I, 871. They are characterized by their low degree of alkalinity, by their very good solubility owing to their numerous hydroxyl groups and, particularly in the case of the compounds in which alkyl groups take the place of the hydrogen atoms at the nitrogen, by their good wetting properties. Most of them are solid and odorless bodies, which properties make them especially advantageous for making trade packages.

These bodies may be used in all kinds of known developers, for example rapid developers, fine grain developers, blue and brown tint developers, negative developers, positive developers, paper developers, reversal developers, and color developers used in the color development processes.

The following 2,181,941 Exmu: 1 Emu 5 v Normal developer v v s l ope Water m- 1000 1 r y fi roxy--methylaminobenzenesu1fat mo 1 hydqxy 4'methylaminobenzen Hate 13 ams" gram" 1 Hydroqulnone grams 3 g i' fi' i "3 Dry sodium sulfite --do 13 e Methylglucamme do Potassium bromide -d0 5.5 Potassium bmmid'e z f" 1 Ethylglucamine -do EXAMPLE 2 Exmm 6 Blue black developer Fine grain developer Water cc" 1000 water Parahe lene diamine ams 10 1 hydroxy -methylaminobenzenesulfate 7 Dry a s; smflte "g 2 Arabinaminens do 5 sg fig Potassium bromide gram 1 Mannamine do 40 EXAMPLE 7 Potassium bromide gram 0.5 develop-er Exmm: 3 Water. cc 1000 Diethyl-para-phenylene diamine grams 8 Brown W Methylglucamine; do 20 1000 What we claim is: v Hydmqmnone "grams" 24 1. Photographic developer comprising develop D sodium sm'fite 60 ing agents and an aliphatic hydroxyalkylamine mctamine d0 80 containing in its molecule at least one alkyl chain Potassium bromide do 2 having at least two hydroxyl groups combined "f with difierent carbon atoms. EXAMPLE 4 2. Photographic-developer comprising developing agents and mannamine. I I l 7 Soft workmg 3. Photographic developer. comprising develop- Water cc 1000 ing agents and lactamine. 1 hydroxy -methylaminobenzenesulfate' 4. Photographic developer comprising developams" 15 lng agents and methylglucamine. Dry sodium sulfite do PAUE GOLDACKER. Xylamine dn GEORGMAISER. Potassium bromide do 2 ERNST SCHMITZ-HILLEBRECHT. 

